wifi: nl80211: split helper function from nl80211_put_iface_combinations

Create a helper function that puts the data from struct
ieee80211_iface_combination to a nl80211 message.
This will be used for adding per-radio interface combination data.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://patch.msgid.link/22a0eee19dbcf98627239328bc66decd3395122c.1719919832.git-series.nbd@nbd.name


Signed-off-by: Johannes Berg <johannes.berg@intel.com>